The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Many mobile computing devices such as cellular phones, tablet computers, notebooks, etc., incorporate global positioning system (GPS) hardware and applications. GPS hardware and applications are useful for navigation with mobile computing devices and are often paired with mobile mapping modules. When instantiated on the device, mobile mapping modules may communicate with a GPS transmitter or other GPS hardware on the device and a backend application server of a mapping system. Using mapping data pushed or pulled from the backend mapping system, the mapping module may then render a digital map of an area around the device's current position on the mobile device. Map data is often pushed to the device from the mapping system based on the device position provided to the system from the GPS hardware via the mapping module. For example, data for graphical representations of streets, buildings, and other geographical features may be pushed to the mobile device and the mapping module running on the device may render the pushed data into images on a display screen of the device based on the current position of the device or based on a search of the mapping system using the device.
To render a map image, a device typically receives raster images from a dedicated server. For example, a map server may operate on the Internet and provide images in a Portable Network Graphics (PNG) format to various client devices for the specified geographic regions. While raster images are relatively easy to render at a client device, raster image data typically requires a large amount of storage space for a comprehensive map. Also, it is difficult to efficiently manipulate raster images at a client device. For example, to zoom in on a selected region, either new raster image data is retrieved from the server, or the available raster image data is enlarged with a noticeable loss in quality.